Tissue prosthesis processing technology

ABSTRACT

A heart valve prostheses crimping apparatus and method for deducing the diameter of stents containing heart valve prosthesis. A medical prosthesis catheter loading apparatus, including a crimping assembly for reducing the diameter of a prosthesis; and a catheter clamp for holding a catheter adjacent to the prosthesis. Also disclosed is an apparatus for reducing the diameter of a medical prosthesis, including a base, a crimp head connectable to the base, and an actuation mechanism connected to the base and connectable to the crimp head to actuate the crimp head. Also disclosed is a method of loading a medical prosthesis into a catheter, including the steps of reducing the diameter of a prosthesis from its normal deployed state to a diameter less than that of the lumen of the catheter; holding a catheter adjacent to the reduced diameter prosthesis; and moving the prosthesis into the catheter lumen.

CROSS-REFERENCE TO RELATED APPLICATIONS, IF ANY

This application claims the benefit under 35 U.S.C. §119(e) ofco-pending U.S. Provisional Patent Application Ser. No. 60/580,244,filed Jun. 16, 2004, which is/are hereby incorporated by reference.

37 C.F.R. §1.71(e) AUTHORIZATION

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the US Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX, IF ANY

Not applicable.

BACKGROUND

1. Field

The present invention relates, generally, to medical devices andmethods. Particularly, the invention relates to tissue prosthesesprocessing apparatus and methods of making and using tissue prosthesesapparatus and systems to process tissue prostheses. More particularly,the invention relates to apparatus and methods for reducing the diameterof tissue prostheses such as heart valves. Most particularly, theinvention relates to a heart valve prostheses crimping apparatus andmethod whereby the diameter of stents containing heart valve prosthesesis reduced.

2. Background Information

The state of the art includes stent crimping and balloon foldingapparatus and methods produced by applicant's assignee, MachineSolutions, Inc. of Flagstaff, Ariz., USA.

A need is believed to exist for the present invention.

All US patents and patent applications, and all other publisheddocuments mentioned anywhere in this application are incorporated byreference in their entirety.

BRIEF SUMMARY

The invention provides a heart valve prostheses crimping apparatus andmethod which are practical, reliable, accurate and efficient, and whichare believed to fulfil the need and to constitute an improvement overthe background technology.

In one aspect, the invention provides a medical prosthesis catheterloading apparatus, comprising a crimping assembly for reducing thediameter of a prosthesis; and a catheter clamp for holding a catheteradjacent to the prosthesis.

In another aspect, the invention provides an apparatus for reducing thediameter of a medical prosthesis, comprising a base, a crimp headconnectable to the base, and an actuation mechanism connected to thebase and connectable to the crimp head to actuate the crimp head.

In a further aspect, the invention provides a method of loading amedical prosthesis into a catheter, comprising the steps of reducing thediameter of a prosthesis from its normal deployed state to a diameterless than that of the lumen of the catheter; holding a catheter adjacentto the reduced diameter prosthesis; and moving the prosthesis into thecatheter lumen.

The features, benefits and objects of the invention will become clear tothose skilled in the art by reference to the following description,claim(s), if any, and drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The present invention, and the manner and process of making and usingit, will be better understood by those skilled in the art by referenceto the following drawings.

FIG. 1 is a perspective view of one embodiment of the tissue prosthesesprocessing apparatus of the present invention.

FIG. 2 is a further perspective view of the apparatus.

FIG. 3 illustrates embodiments of the tub, catheter clamp and crimpingassemblies of the apparatus.

FIG. 4 is an exploded view of the crimping assembly of the apparatus.

FIG. 5 is a perspective view of the crimping assembly.

FIG. 6 is a perspective view of the crimping assembly showing anembodiment of the activation ring.

FIG. 7 is a perspective view of the back side of an embodiment of thestationary plate of the crimping assembly.

FIG. 8 is a perspective view of the back side of an embodiment of themain face plate of the crimping assembly.

FIG. 9 is an exploded view of an embodiment of the quick change catheterclamp of the apparatus.

FIGS. 10-15 illustrate a process of using the quick change catheterclamp.

FIG. 16 is a perspective view of an alternative embodiment of thecrimping assembly of the apparatus.

FIG. 17 is a front elevation view of the crimping assembly of FIG. 16.

FIG. 18 is a top plan view thereof.

FIG. 19 is an end view thereof.

FIG. 20A is another perspective view of the crimping assembly, showingelement loading of a fresh set of elements using a loader.

FIG. 20B is an exploded view of the crimping assembly.

FIG. 21A-B illustrate an embodiment of the activation ring of thecrimping assembly.

FIG. 22 is a perspective view of an embodiment of the disposablecrimping head of the crimping assembly, also showing the loader.

FIG. 23 is an exploded view of the crimping head, also showing theloader.

FIG. 24 is a perspective view of embodiments of the base and plates ofthe crimping assembly.

FIG. 25 is a front elevation view of the crimp head.

FIG. 26 is a perspective view of an embodiment of a crimping element orsegment of the crimping head shown in FIGS. 4 and 6.

FIG. 27 is a perspective view of an alternative embodiment of a crimpingelement for use with the crimping head shown in FIGS. 16-25.

FIG. 28 is a view showing the opposite sides in phantom.

FIG. 29 is a view of the lateral side of the segment.

FIG. 30 is a view of the longitudinal side of the segment.

FIG. 31 is a view of the distal end of the segment.

DETAILED DESCRIPTION

The tissue prosthesis crimping apparatus of the present invention isuseable by a single operator to easily reduce the diameter of, or crimp,relatively large stents containing tissue prostheses such as heartvalves and the like, and loads such device into a catheter for later useand deployment in a patient. It is suitable “bed-side” catheterprocedures such as minimally invasive heart valve replacement (MIHVR).The tissue prosthesis crimping apparatus is also useable for benchtesting medical devices and product testing such devices with animals.

Referring first to FIGS. 1-3, the tissue prosthesis crimping apparatus10 for loading a prosthesis or other medical device (not shown) into acatheter or sheath 11, or other tubular structure comprises, in general,a crimping assembly 12, a submersion tank or tub 13 for holding amedical solution 14 such as saline, and catheter clamp 15. The apparatus10 operates while partially submerged in the saline solution 14 which iscontained in the removable tub 13. Tank 13 is preferably about 13×7.5inches, with a height of about 5.25 inches, a maximum liquid volume ofabout 5.15 liters and a filled weight of about 15 lbs. Only a singleperson is required to perform all operations of the apparatus. A base orframe portion 19 of the crimping assembly and the catheter clamp 15 arereusable and can be steam and EtO sterilized. All parts in directcontact with the stent or prosthesis, including the crimping elements orsegments (described below) of a crimp head or assembly 20, are one-usedisposable pieces that are easily interchanged between procedures.

In general, operation of the system 10 first involves placing new crimpelements or segments into the crimp head 20 (preferably with theassistance of a loader), and moving it to a full open position. Next,the machine base 19, including the head 20, is placed into the tub 13.The catheter 11 is secured to the quick release clamp 15. The clamp 15is secured to the base 19. Next, a prosthesis mated with a stent isinserted into the head 20 for example by hand, and the head 20 isactuated, which closes a central aperture thereof, until the individualcrimp elements rest against hard stops. This radially compresses orcrimps the stent/prosthesis. The crimped device is pushed (for examplevia a quill) or pulled (via a device internal to the catheter) into thecatheter 11. This apparatus is useable with both balloon expandable andself expanding prosthesis stents. The catheter clamp 15 is removed fromthe base 19. Finally, the catheter 11 is removed from the clamp 15 withthe crimped prosthetic device, for example a heat valve, installedtherein.

Referring also to FIGS. 4-6, the crimping assembly 12 comprises the baseor frame 19, the crimp head 20, and an actuation mechanism 21 connectedto the frame and connectable to the crimp head 20. The apparatus alsopreferably includes an attachable loader 22 for aligning and loading theelements of the crimp head 20 onto actuation mechanism 21.

Referring also to FIGS. 7 and 8, the frame 19 comprises a base member25, a pair of crimp head retaining members comprising a front plate 26and a rear plate 27, and side members 28 a and b. The base member 25provides bottom support for the remaining elements of the frame 19. Thefront and rear plates 26 and 27 extend upwardly from the base member 25and are separated a predetermined distance. Front plate 26 has aremovable face plate 29. Face plate 29 and rear plate 26 each have apredetermined arrangement of linear, angled slide grooves or slots 30disposed on their inwardly facing surfaces, surrounding coaxial centralapertures 35 a and b. Each groove configuration 30 preferably have apair of concentric members which cooperate with slide members on thehead 20 elements to provide linear, radial movement to compress thestent/prosthesis, as described later.

Referring also to FIG. 26 the crimp head 20 comprises a plurality, forexample eight (8) crimp segments or elements 34 a-h which are arrangedabout and define a central aperture 35. Each segment 34 has apredetermined configuration with an inwardly oriented tapered distal end36 which is disposed toward the aperture 35 and an outwardly orientedproximal end 37. A pair of distal rectilinear slide blocks or shoulders38 a and b are disposed on the longitudinally oriented (with respect tothe working or input/output axis of the apparatus 10 in general) ends ofthe segment 34. A pair of proximal slide blocks 39 a and b are disposedproximally. The slide blocks 38 and 39 mate with slide grooves 30 of theplates 26 and 27. Preferably, at least one loader mating aperture isdisposed at each longitudinal end for connection to a loader (notshown). The elements 34 have predetermined substantially flat lateralfaces 41 a and b which cooperate with the actuator 21, the slide blocks39 and the slide grooves 30 to move the elements 34. The distal ends arepreferably about 50 mm in length.

As is best shown in FIG. 6, the actuator 21 comprises activation ring43, rollers 47, arms 49, beam 50 and screw 51. A handle 52 is connectedto the screw 51 for hand turning by the operator. The screw 51threadedly connected to an end of the beam 50, which is pivotallyconnected at pin/aperture 53 to the plates 26 and 27. Arms 49 a and bare pivotally connected to the beam 50 at one end and to the ring 43 atthe other end, via brackets 48 a and b. Ring 43 is preferablybifurcated, but may have a unitary structure. Ring 43 has acircumferential ring portion 45 and a plurality radial spokes 46 a-galigned between the crimp elements 34. Rollers 47 a-h are connected tospokes 46. Rotation of the screw 51 moves the beam 50, which moves thearms 49 and causes them to rotate the activation ring 43. This causesrollers 47 to contact and move along the lateral faces 41 of thesegments 34. The rotary force of the rollers 47 causes the segments 34to linearly slide along a predetermined path determined by grooves 30 asa result of slide blocks 39. The distal ends 36 of the segments movetoward one another whereby the aperture 35 becomes smaller and closes.The ends 36 engage and radially compress the prosthetic device disposedin the aperture 35.

The preferred maximum opening diameter of the crimp head 20 aperture 35is about 35 mm and it can close to substantially zero mm. Utilizing theteachings of this invention, the maximum crimping force of the apparatus10 is about 100 lbs. between two opposing elements 34. Maximum crimpingcycles is about 10 per head 20.

Referring to FIGS. 9-15, the catheter clamp 15 comprises a front plate68 connected to a bottom block 69, a top block 70 and a spring clamp 71.A catheter 11 is placed in a central groove or channel of the bottomblock 69 so that its open terminal or distal end abuts the front plate68. As is known in the art, the catheter 11 has a hollow lumen. Topblock 70 is placed over the bottom block so that its groove is alignedwith the catheter 11. Clamp 71 is placed over the mated blocks 69 and 70to hold them in place. Front plate 68 is connectable to the crimpingassembly 12 so that the radially compressed, reduced diameter prosthesiscan be pushed or pulled into the catheter 11 lumen via its open end. Theclamp 15 will accommodate sheaths 11 up to about 8 mm in diameter andabout 65 mm in length. Stent diameter reductions of at least 6 mm areobtained.

Operation of the apparatus 10 is relatively simple, which minimizes theneed for special operator training. Final close diameter is dependent onthe specific crimping elements 34 chosen for a procedure, whichsubstantially minimizes the possibility of operator calibration error.The crank handle 52 requires minimal physical effort to provide adequatecrimping force. Introduction of the crimped stent can be accomplished bytwo means. A hand held quill can be used to manually push the crimpedstent out of the base and into the catheter, or the stent may be pulledout of the base and into the catheter by means of an internal catheterdevice. The catheter clamp set 15 accommodates a wide range of frenchcatheter sizes. The clamps 15 are quickly and easily detached andattached to the apparatus base, which reduces operation cycle time andallows for simple catheter placement. The design of the clamps 15 alsoprovides superior alignment of the stent for insertion into the catheterwhen compared to other stent introduction means. The insertion apertureof the apparatus 10 minimizes gapping between crimping elementsthroughout its entire diameter range, which avoids damage to stentsduring compression. The small size and weight of the apparatus 10 allowsfor easy storage and transportation.

The modular design of the system 10 also provides several advantages,including disposable element capability, reduced procedure cycle time,reduced storage space requirement, and reduced space requirement forsterilizing procedures. The disposable crimp elements 20 eliminatesurface cross-contamination between procedures and allow preset closediameter settings on future machines. The quick-connect catheter clamp15 allows fast and accurate location of sheath 11 within the clamp 15and quick attachment/detachment of clamp 15 to the base 12. They alsoprevent the base 12 from interfering with sheath loading by allowingoperators to load the sheath 11 while the clamp 15 is not attached tothe base. The C-clamp spring 71 allows quick release and removal of topclamp plate 70 and catheter 11, while doubling as a holding grip. In oneembodiment, turn crank 52 and power screw activation provides adequateholding ability at closed position under crimping loads while requiringlittle effort from the operator. Linearly moving crimping elements 34reduces gapping between crimping elements 34 during aperture reduction.This also allows for development of zero gapping throughout the entiretravel using injection-molded elements 34. Additionally, it permitsreduction of the overall size of the machine 10, as well as thedisposable elements 34. Quick-change elements 34 or elements set 20permits easy transportation, sterilization, and loading of thedisposable element set 20. It also avoids damage of the crimpingelements 24 during shipping and assures correct placement within themachine base 12. The separate submersion tank 13 reduces space requiredfor machine storage, allows the machine to be moved in pieces, andsimplifies watertight sealing. An adjustable hard stop embodiment allowsfast close diameter adjustment for testing purposes. Polymer plainbearings allow for steam and EtO sterilization while reducing pivotpoint friction and eliminating corrosion. Lower adjustable bearing axlespermit preloading of polymer roller bearings against activation rings.

Referring to FIGS. 16-19, an alternative embodiment of the crimpingassembly 112 comprises the base or frame 119, the crimp head 120, and anactuation mechanism 121 connected to the frame 119 and connectable tothe crimp head 120. The apparatus also preferably includes an attachableloader 122 for aligning and loading the elements of the crimp head 120onto actuation mechanism 121.

Referring also to FIGS. 20 and 24, the frame 119 comprises a base member125, a front frame 126 and a rear frame 127. The base member 125provides bottom support for the remaining elements of the frame 119. Thefront and rear plates 126 and 126 extend upwardly from the base member125 and are separated a predetermined distance. Front plate 126 has aremovable face plate 129. Face plate 129 and rear plate 126 each have apredetermined arrangement of linear, angled slide grooves or slots 130disposed on their inwardly facing surfaces, surrounding coaxial centralapertures 135 a and b. The groove configuration 130 preferably includesa pair of concentric members which cooperate with slide members on thehead 120 elements to provide linear, radial movement to compress thestent/prosthesis.

Referring also to FIGS. 22, 23, and 25 the crimp head 120 comprises aplurality, for example eight (8) crimp segments or elements 134 a-hwhich are arranged about and define a central aperture 135. As is bestshown in FIGS. 27-31, each segment 134 has a predetermined configurationwith an inwardly oriented tapered distal end 136 which is disposedtoward the aperture 135 and an outwardly oriented proximal end 137. Apair of distal rectilinear slide blocks or locating shoulders 138 a andb are disposed on the longitudinally oriented (with respect to theworking or input/output axis of the apparatus 10 in general) ends of thesegment 134. A pair of proximal slide blocks 139 a and b are disposedproximally. The slide blocks 138 and 139 mate with slide grooves 130 ofthe plates 126 and 127. Preferably, at least one loader mating aperture171 is disposed at each longitudinal end for connection to a loader 122a and b. The elements 134 have predetermined substantially flat lateralfaces 141 a and b of a predetermined inset configuration on one side,which cooperate with the actuator 121, the slide blocks 139 and theslide grooves 130 to move the elements 134. The distal ends arepreferably about 50 mm in length.

Returning to FIGS. 20, 21 and 24 the actuator 121comprises activationring 143 with an external gear tooth profile 144 and a plurality ofactivation pin structures 147 disposed on its interior. The activationring 143 is held in rotatable place between plates 126 and 127 by acapture plate lock ring 145. A handle 152 is connected to the frontplate 126 via a pin 148 at point 149. Handle end has a drive gear 150which mates with gear tooth profile 144 of activation ring 143. Rotationof the arm 152 moves the gear 150, which moves the activation ring 143.This causes pins 147 to contact and move along the lateral faces 141 ofthe segments 134. The rotary force of the pins 147 causes the segments134 to linearly slide along a predetermined path determined by grooves130 as a result of slide blocks 139. The distal ends 136 of the segmentsmove toward one another whereby the aperture 135 becomes smaller andcloses. The ends 136 engage and radially compress the prosthetic devicedisposed in the aperture 135.

Base 119 further preferably also has segment load position indicatinggraphics 155, an activation ring locating slot 156, and a handle loadposition indicator 157 for ease of head 120 replacement.

The descriptions above and the accompanying drawings should beinterpreted in the illustrative and not the limited sense. While theinvention has been disclosed in connection with an embodiment orembodiments thereof, it should be understood by those skilled in the artthat there may be other embodiments which fall within the scope of theinvention as defined by the claims. Where a claim, if any, is expressedas a means or step for performing a specified function it is intendedthat such claim be construed to cover the corresponding structure,material, or acts described in the specification and equivalentsthereof, including both structural equivalents and equivalentstructures, material-based equivalents and equivalent materials, andact-based equivalents and equivalent acts.

1. A medical prosthesis catheter loading apparatus, comprising: a. acrimping assembly for reducing the diameter of a prosthesis, thecrimping assembly comprises a base, a crimp head connectable to thebase, and an actuation mechanism connected to the base and connectableto the crimp head to actuate the crimp head, wherein the base comprisesa pair of crimp head retaining members, the retaining members beingconstructed of a sterilizable material, crimp elements, and having acrimp head element guide with at least two concentric arrangements oflinear grooves; and b. a catheter clamp for holding a catheter adjacentto the prosthesis.
 2. The apparatus of claim 1, wherein the crimp headcomprises a plurality of crimp elements arranged about a central crimpaperture.
 3. The apparatus of claim 2, wherein the elements linearlymove to vary the size of the central crimp aperture.
 4. The apparatus ofclaim 2, wherein each crimp element has a distal end disposed near thecentral aperture and a proximal end disposed away from the centralaperture, each element further having a distal rectilinear slide block,a proximal rectilinear slide block, and at least one flat actuationsurface.
 5. The apparatus of claim 2, wherein the head is readilydisposable.
 6. The apparatus of claim 5, further comprising an elementloader for configuring the crimp elements.
 7. The apparatus of claim 2,wherein the actuation mechanism comprises a rotatable activation ringcommunicatively connected to the crimp elements to move them linearlytoward the central crimp aperture.
 8. The apparatus of claim 7, whereinthe activation ring is communicatively connected to the crimp elementsvia element contacting rollers.
 9. The apparatus of claim 7, wherein theactivation ring is communicatively connected to the crimp elements viaelement contacting pins.
 10. The apparatus of claim 7, wherein theactuation mechanism further comprises a screw connected to theactivation ring via a lever arrangement.
 11. The apparatus of claim 7,wherein the actuation mechanism further comprises an arm connected tothe activation ring via a gear arrangement.
 12. The apparatus of claim1, wherein the catheter clamp comprises a pair of blocks, each havingslot for engaging a portion of a catheter, and a clamp for holding theblocks together, the blocks and clamp being constructed of asterilizable material.
 13. The apparatus of claim 12, wherein at leastone block has a face for connecting to the crimping assembly.
 14. Theapparatus of claim 1, further comprising a submersion tank for holding apredetermined amount of a medical solution and adapted for enclosing atleast a portion of the crimping assembly and the catheter clamp.